Non-MMO survival

Lerxst

I have a rather decent sized library of survival games. Some are online, most I play solo. Looking for one I may have missed along the way.

I like the ones that make you think, struggle and survive against an immediate threat - 7 Days to Die = zombies, The Forest = cannibals, Empyrion - AI drones, etc. Too many either lack this threat, or just get way too easy, way too fast. I also really enjoy the terraforming aspect many of the games have. Just building on top of everything seems unnatural to me.

Wondering if there are any out there I may not have tried yet, or have been massively updated over the past couple years. 

Recently, I've played:

Empyrion - love it but gets boring fast
ARK (and hated it)
Avorion - enjoy it but lots of bugs still and not quite "survival".
7 Days to Die - one of my "go to" games for this genre
Conan Exiles - Too much like Rust or ARK.
TerraTech - like it, but lacks most of the real survival elements.

Suppose I'm looking for more like 7 Days to Die - building, terraforming, serious threat and major reason to stock up and defend every 7 days.

Reizla

No Man's Sky. While it's been bashed dramatically, I picked it up this week (along with my PS4 Pro) and I love it (prolly because of the heavy patching/updating since launch). The game has 3 difficulties of which one is a survival mode where the security drones are maxed out and you encounter more hostile creatures on the planets.

frostymug

A few you didn't list that I have enjoyed:
Salt
The Long Dark
Subnautica

Might be worth checking out, but might not be your cup of tea. I personally enjoy more exploring type survival games whereas it sounds like you enjoy the hunker down survival type. Salt has a demo if you wanted to give it a run. None have terraforming. Subnautica doesn't even really have terra. The Long Dark is the most hardcore and has pretty nice stylized graphics and permadeath with a leaderboard for longest survivals. Subnautica is gorgeous and very atmospheric. Salt has pirates and the quickest way into my library is pirates or Warhammer.

Lerxst

Aye, Subnautica was definitely a fun game to play for a while. I built a small base, explored a lot, but ultimately found that I preferred the constant threat of looking over my shoulder and dying with brutal penalties that games like 7 days to Die provided. 

Digging around deep in the ocean just to turn a corner and see a huge ass creature with teeth coming down around your little sub, was worth the jump scare at times though